Recently, inkjet-printing has gained increased popularity in applications such as flexible electronics and disposable sensors, as well as in wearable sensors because of its multifarious advantages. This work presents a novel, low-cost immobilization technique using inkjet-printing for the development of an aptamer-based biosensor for the detection of lysozyme, an important biomarker in various disease diagnosis. The strong affinity between the carbon nanotube (CNT) and the single-stranded DNA is exploited to immobilize the aptamers onto the working electrode by printing the ink containing the dispersion of CNT-aptamer complex. The inkjet-printing method enables aptamer density control, as well as high resolution patternability. Our developed sensor shows a detection limit of 90 ng/mL with high target selectivity against other proteins. The sensor also demonstrates a shelf-life for a reasonable period. This technology has potential for applications in developing low-cost point-of-care diagnostic testing kits for home healthcare.

Commercially available bulk niobium diselenide (NbSe2) reduced into nanomaterials upon exfoliation typically contains oxide and carbide impurities. Liquid-phase exfoliated two-dimensional (2D) nanosheets of NbSe2 obtained from bulk powders provide high charge mobility and large surface area but become self-passivated and chemically inert as the presence of oxide impurities makes them behave more semimetallic. In this article, we report the effects of inherent impurities of liquid-phase exfoliated 2D NbSe2 (intended to be integrated as supercapacitor electrodes) on the electrochemical performance. The highest specific capacitances achieved using 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6) and sulfuric acid (1 M H2SO4) electrolytes were 4955.5 ± 21.5 and 13 361.6 ± 31.8% mF/cm2, respectively, which were affected by the impurities, oxophilicity of niobium defects, and moisture adsorption in the cell. Galvanostatic charge–discharge profiles show moisture adsorption affecting the high-energy charging procedure in the cell for BMIMPF6, resulting in leakage and decomposition of the electrolyte. Electrochemical impedance spectroscopy provides insights into the solid-electrolyte interphase and charge-transfer mechanisms at exfoliated 2D NbSe2 nanosheets, which affect the ion intercalation through heterogenous phases of the nanosheets. Overall, the NbSe2 nanosheets offer heterogenous phases because of the coexistence of Nb2O5 that influences the charge-transfer mechanism at the exfoliated surfaces.

The integration of biomolecules such as proteins, carbohydrates, or enzymes into functional materials, whether through physical or chemical coupling, remains a critical processing step in the fabrication of engineered biosensors or tissue scaffolds, where anisotropy and composition can directly impact material function and host integration. A means to achieve these features is through the selective patterning of biomolecules, which is used to recruit and direct cell growth in vitro. The authors describe the design of protein-based materials using inkjet printing and discuss how fluid physical properties of the formulated inks influence pattern formation and material performance. When interfaced with carbon nanotubes, the biohybrid films retain their chemical signature but with enhanced structural stability and electrical conductivity over time. These structures also support the adhesion and proliferation of human dermal fibroblasts. Together, these properties demonstrate the utility of printed biohybrid films as materials that can conceivably be used to recapitulate or enhance biological function for tissue engineering applications.